Controlled deployable medical device and method of making the same

ABSTRACT

Controlled deployable medical devices that are retained inside a body passage and in one particular application to vascular devices used in repairing arterial dilations, e.g., aneurysms. Such devices can be adjusted during deployment, thereby allowing at least one of a longitudinal or radial re-positioning, resulting in precise alignment of the device to an implant target site.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a continuation of U.S. patent application Ser. No.14/208,441, filed Mar. 13, 2014, now U.S. Pat. No. 10,219,925, issuedMar. 5, 2019, which is a continuation of U.S. patent application Ser.No. 12/478,331, filed Jun. 4, 2009, now abandoned, which claims thebenefit of U.S. Provisional Application 61/058,776, filed Jun. 4, 2008,all of which are incorporated herein by reference in their entiretiesfor all purposes.

BACKGROUND OF THE INVENTION Field of the Invention

The invention relates generally to devices that are retained inside abody passage and in one particular application to vascular devices usedin repairing arterial dilations, e.g., aneurysms. More particularly, theinvention is directed toward devices that can be adjusted duringdeployment, thereby allowing at least one of a longitudinal or radialre-positioning of the device prior to final placement of the device.

Discussion of the Related Art

The invention will be discussed generally with respect to deployment ofa bifurcated stent graft into the abdominal aorta but is not so limitedand may apply to device deployment into other body lumens. Whendelivering a stent graft by intraluminal or endovascular methods, it isimportant to know the precise location of the device in the vasculature.Controlling this precise location is particularly important when thedevice is intended to be deployed in close proximity to branch vesselsor adjacent to weakened portions of the aortic wall. Typical stentgrafts used to repair an aortic aneurysm incorporate a proximal (i.e.portion of the stent graft closest to the heart) anchoring systemintended to limit longitudinal displacement of the stent graft. Oftenthis anchoring system must be precisely placed to avoid occlusion of abranch vessel or to avoid placement within a compromised and damagedportion of the aortic wall.

An improved delivery system for such stent grafts would include a meansfor allowing precise longitudinal and rotational placement of the stentgraft and anchoring system. The precise position of the stent graft andanchoring system would be adjusted and visualized prior to fulldeployment of the device. Ideally the delivery system would allow thedevice to be repositioned if the prior deployment position wasundesirable.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings are included to provide a furtherunderstanding of the invention and illustrate certain aspects of theinvention.

In the drawings:

FIG. 1A is a medical apparatus according to an embodiment of theinvention.

FIG. 1B is an enlarged simplified view of the medical apparatusaccording to an embodiment of the invention.

FIG. 1C is a medical apparatus according to an embodiment of theinvention.

FIG. 1D is an enlarged simplified view of the medical apparatusaccording to a second embodiment of the invention.

FIG. 2A is a medical apparatus according to an embodiment of theinvention.

FIG. 2B is an enlarged simplified view of a medical apparatus accordingto an embodiment of the invention.

FIG. 2C is a medical apparatus according to an embodiment of theinvention.

FIG. 2D is an enlarged simplified view of a medical apparatus accordingto an embodiment of the invention.

FIG. 3A is a medical apparatus according to an embodiment of theinvention.

FIG. 3B is an enlarged simplified view of a medical apparatus accordingto an embodiment of the invention.

FIG. 3C is an enlarged simplified view of a medical apparatus accordingto an embodiment of the invention.

FIG. 4A is a medical apparatus according to an embodiment of theinvention.

FIG. 4B is an enlarged simplified view of a medical apparatus accordingto an embodiment of the invention.

FIG. 5A is a medical apparatus according to an embodiment of theinvention.

FIG. 5B is an enlarged simplified view of a medical apparatus accordingto an embodiment of the invention.

FIG. 6A is a medical apparatus according to an embodiment of theinvention.

FIG. 6B is an enlarged simplified view of a medical apparatus accordingto an embodiment of the invention.

FIG. 7A is a medical apparatus according to an embodiment of theinvention.

FIG. 7B is an enlarged simplified view of a medical apparatus accordingto an embodiment of the invention.

FIGS. 8A-8C is a medical apparatus according to an embodiment of theinvention.

FIG. 9A is an apparatus according to an embodiment of the invention.

FIG. 9B is a cross-sectional view of FIG. 9A along line A to A′.

FIGS. 10A-10H illustrates a deployment procedure of an apparatusaccording to FIGS. 2A-2B.

DETAILED DESCRIPTION

The invention relates generally to a novel medical apparatus thatincludes a device capable of being retained inside a body passage and inone particular application to vascular devices. More particularly, theinvention is directed toward devices that can be adjusted duringdeployment, thereby allowing at least one of a longitudinal or radialre-positioning of the device.

In an embodiment of the invention, the medical apparatus includes acatheter assembly having a proximal end portion and distal end portion.A hub can optionally be arranged on the distal end portion of thecatheter assembly. A stent is arranged on the proximal end portion ofthe catheter. The stent has an inner surface and an outer surface. Thestent can be any suitable configuration. In one embodiment, the stent isconfigured from multiple turns of an undulating element. A graft membercan be arranged about at least a portion of the stent. The stent may beself-expandable, balloon-expandable or a combination of self-expandableand balloon-expandable.

A tube extends from the proximal end portion to the distal end portionof the catheter. A first movable element, having a first and second end,is arranged around the outer surface of the stent. The first and secondend of the first movable element are capable of extending out the distalend portion of the tube and the first movable element is capable ofradially compressing at least a portion of the stent.

Optionally, a second movable element can be in communication with thefirst movable element, wherein the second movable element is arrangedaround the outer surface of stent and the first movable element islooped over the second movable element. A sheath material can cover atleast a portion of the stent, wherein the sheath material is capable ofholding the stent at a first diameter. A filament can surround the stentand a pin can extend from the tube and is capable of holding thefilament surrounding the stent at a second diameter which is greaterthan the first diameter. The pin extending from the tube is capable ofreleasing the filament surrounding the stent to a third diameter whichis greater than the second diameter.

In some embodiments, the stents can be used to at least fix the medicalapparatus inside a portion of patient's anatomy. The stent can beconstructed from materials that are flexible and strong. The stent canbe formed from, for example, degradable bioabsorable materials,biodigestible materials, polymeric materials, metallic materials andcombinations thereof. In addition, these materials may be reinforcedand/or coated with other materials, such as polymeric materials and thelike. The coating may be chosen to reduce acidic or basic effects of thegastrointestinal tract, e.g., with a thermoplastic coating such as ePTFEand the like.

The stents can be fabricated using any suitable methods and materials.For example, stents can be fabricated according to the teachings asgenerally disclosed in U.S. Pat. No. 6,042,605 issued to Martin, et al.,U.S. Pat. No. 6,361,637 issued to Martin, et al. and U.S. Pat. No.6,520,986 issued to Martin, et al. For example, stents can have variousconfigurations as known in the art and can be fabricated, for example,from cut tubes, wound wires (or ribbons), flat patterned sheets rolledinto a tubular form, combinations thereof, and the like. Stents can beformed from metallic, polymeric or natural materials and can compriseconventional medical grade materials such as nylon, polyacrylamide,polycarbonate, polyethylene, polyformaldehyde, polymethylmethacrylate,polypropylene, polytetrafluoroethylene, polytrifluorochlorethylene,polyvinylchloride, polyurethane, elastomeric organosilicone polymers;metals such as stainless steels, cobalt-chromium alloys and nitinol andbiologically derived materials such as bovine arteries/veins,pericardium and collagen. Stents can also comprise bioresorbablematerials such as poly(amino acids), poly(anhydrides),poly(caprolactones), poly(lactic/glycolic acid) polymers,poly(hydroxybutyrates) and poly(orthoesters).

The stents can be formed into a variety of different geometricconfigurations having constant and/or varied thickness as known in theart. The geometric configurations may include many conventional stentconfigurations such as a helically wrapped stent, z-shape stent, taperedstent, coil stent, combinations thereof, and the like. The stents can beformed in a variety of patterns, such as, a helix pattern, ring pattern,combinations thereof, and the like.

Grafts can have various configurations as known in the art and can befabricated, for example, from tubes, sheets or films formed into tubularshapes, woven or knitted fibers or ribbons or combinations thereof.Graft materials can include, for example, conventional medical gradematerials such as nylon, polyester, polyethylene, polypropylene,polytetrafluoroethylene, polyvinylchloride, polyurethane and elastomericorganosilicone polymers.

Stents can be used alone or in combination with graft materials. Stentscan be configured on the external or internal surface of a graft or maybe incorporated into the internal wall structure of a graft. Stent orstent grafts can be delivered endoluminally by various catheter basedprocedures known in the art. For example self-expanding endoluminaldevices can be compressed and maintained in a constrained state by anexternal sheath. The sheath can be folded to form a tube positionedexternal to the compressed device. The sheath edges can be sewn togetherwith a deployment cord that forms a “chain stitch”. To release anddeploy the constrained device, one end of the deployment cord can bepulled to disrupt the chain stitch, allowing the sheath edges toseparate and release the constrained device. Constraining sheaths anddeployment cord stitching can be configured to release a self-expandingdevice in several ways. For example a constraining sheath may release adevice starting from the proximal device end, terminating at the distaldevice end. In other configurations the device may be released startingfrom the distal end. Self expanding devices may also be released fromthe device center as the sheath disrupts toward the device distal andproximal ends.

Details relating to constraining sheath materials, sheath methods ofmanufacture and stent graft compression techniques can be found in, forexample, U.S. Pat. No. 6,352,561 issued to Leopold, et al., and U.S.Pat. No. 6,551,350 issued to Thornton, et al.

The catheter and hub assemblies can comprise conventional medical gradematerials such as nylon, polyacrylamide, polycarbonate, polyethylene,polyformaldehyde, polymethylmethacrylate, polypropylene,polytetrafluoroethylene, polytrifluorochlorethylene, polyether blockamide or thermoplastic copolyether, polyvinylchloride, polyurethane,elastomeric organosilicone polymers, and metals such as stainless steelsand nitinol.

Turning to the figures, FIG. 1A is a medical apparatus according to anembodiment of the invention. FIG. 1B is an enlarged simplified view of aportion of the medical apparatus shown in FIG. 1A.

Referring to FIGS. 1A and 1B, the medical apparatus is generallydepicted as reference numeral 100A. The medical apparatus 100A includescatheter assembly 102, stent 104 arranged on the proximal end portion ofthe catheter assembly 102. The stent 104 has an inner surface, an outersurface, and in this embodiment is configured from multiple turns of anundulating element 105. The undulating element 105 can be configured,for example, in a ring or helical pattern.

The stent 104 has a proximal end portion 106 and distal end portion 108.The distal end portion 108 is formed into a branch having a first leg110 and a second leg 112.

A graft member 114 is arranged about the stent 104.

The stent 104 and graft member 114 are constrained into a compacteddelivery state by a first sheath 116 and second sheath 118. As shown inFIG. 1A, the first sheath 116 has been released, allowing at least aportion of the stent 104 to expand as shown. The second sheath 118 iscoupling the second leg 112 to the catheter assembly 102 as shown.

A tube 120 extends from a proximal end portion to a distal end portionof the catheter assembly 102. In the figure, the tube 120 is positionedadjacent the outer surface of the stent 104 and graft 114. The tube 120is attached to the catheter assembly 102 and not attached to the stent104 or graft 114. A movable element 122 (e.g., a fiber cord, string,wire, etc.) having a first end 124 and second end 126 surrounds thestent 104 and graft member 114. The first end 124 and second end 126 ofthe movable element 122 extend out a distal end portion of the tube 120.For example, the movable element 122 is threaded through the tube from adistal end to a proximal end and is looped around the proximal endportion 106 of the stent 104 and graft member 114. As shown in FIG. 1B,by pulling the first end 124 and the second end 126 in a distaldirection the movable element 122 is capable of radially compressing atleast a portion of the stent 104 as indicated by arrows 128.

FIG. 1C is a medical apparatus according to an embodiment of theinvention. FIG. 1D is an enlarged simplified view of a portion of themedical apparatus shown as FIG. 1C.

Referring to FIGS. 1C and 1D, the medical apparatus is generallydepicted as reference numeral 100B. The medical apparatus of FIGS. 1Cand 1D is similar to the medical apparatus as shown in FIGS. 1A and 1B.The medical apparatus includes catheter assembly 102, stent 104 arrangedon the proximal end portion of catheter assembly 102. Stent 104 has aninner surface, an outer surface, and is configured from multiple turnsof an undulating element 105. The undulating element 105 may beconfigured, for example, in a ring or helical pattern.

The stent 104 has a proximal end portion 106 and distal end portion 108.The distal end portion 108 is formed into a branch having a first leg110 and a second leg 112.

A graft member 114 is arranged about the stent 104.

The stent 104 and graft member 114 are constrained into a compacteddelivery state by a first sheath 116 and second sheath 118. As shown inFIG. 1C, the first sheath 116 has been released allowing at least aportion of the stent to expand as shown. The second sheath 118 iscoupling the second leg 112 to the catheter assembly 102 as shown.

A tube 120 extends from a proximal end portion to a distal end portionof the catheter assembly 102. The tube 120 is positioned adjacent theouter surface of the stent 104 and graft 114. The tube 120 is attachedto the catheter assembly 102 and not attached to the stent 104 or graft114. A movable element 122A having a first end 124 and second end 126surrounds the stent 104 and graft member 114. The first end 124 andsecond end 126 of the movable element 122A extend out a distal endportion of the tube 120. For example, the movable element 122A isthreaded through the tube from a distal end to a proximal end and islooped around the proximal end portion 106 of the stent 104 and graftmember 114.

Moreover, an additional movable element 122B having first end 132 andsecond end 134 surrounds the stent 104 and graft member 114. The firstend 132 and second end 134 of the additional movable element 122B extendout a distal end portion of the tube 120. The additional movable element122B is threaded through the tube from a distal end to an intermediateopening 136 in the tube 120 and is looped around an intermediate portionof the stent 104 and graft member 114. As shown in FIG. 1D, by pullingthe ends of the moveable elements in a distal direction the movableelement 122A and the additional movable element 122B are capable ofradially compressing at least a portion of the stent 104 as indicated byarrows 128. It should be understood that additional moveable elementscan be provided.

FIG. 2A is a medical apparatus according to an embodiment of theinvention, shown in a partially deployed state. FIG. 2B is an enlargedsimplified view of a portion of the medical apparatus shown in FIG. 2A.

Referring to FIGS. 2A and 2B, the medical apparatus is generallydepicted by reference numeral 200A. The medical apparatus 200A includesa catheter assembly 202, and stent 204 arranged on the proximal endportion of the catheter assembly 202. The stent 204 has an innersurface, an outer surface, and is configured from multiple turns of anundulating element 205. The undulating element 205 can be configured,for example, in a ring or helical pattern.

The stent 204 has a proximal end portion 206 and distal end portion 208.The distal end portion 208 is formed into a branch having a first leg210 and a second leg 212.

A graft member 214 is arranged about the stent 204.

The stent 204 and graft member 214 are constrained into a compacteddelivery state by a first sheath 216 and second sheath 218. As shown inFIG. 2A, the first sheath 216 has been released allowing at least aportion of the stent to expand. The second sheath 218 is coupling thesecond leg 212 to the catheter assembly 202 as shown.

A tube 220 extends from a proximal end portion to a distal end portionof the catheter assembly 202. In this embodiment, the tube 220 ispositioned adjacent the outer surface of the stent 204 and graft 214. Inthis embodiment, the tube 220 is attached to the catheter assembly 202and not attached to the stent 204 or graft 214.

A second movable element 236 is in communication with a first movableelement 222. The second movable element 236 surrounds the stent 204 andthe first movable element 222 is looped through the second movableelement 236.

The first end 224 and second end 226 of the first movable element 222extend out a distal end portion of the tube 220. For example, the firstmovable element 222 is threaded through the tube from a distal end to aproximal end and is looped through the second movable element 236.

As shown in FIG. 2B, when the two ends 224 and 226 of the first movableelement are pulled in a distal direction, the movable element 222 pullson the second movable element 236, radially compressing at least aportion of the stent 204 as indicated by arrows 228.

FIG. 2C is a medical apparatus according to an embodiment of theinvention. FIG. 2D is an enlarged simplified view of a portion of themedical apparatus shown in FIG. 2C.

Referring to FIGS. 2C and 2D, the medical apparatus is generallydepicted by reference numeral 200B. The medical apparatus of FIGS. 2Cand 2D is similar to the medical apparatus as shown in FIGS. 2A and 2B.

Shown in FIGS. 2C and 2D, a second movable element 236A is incommunication with a first movable element 222A. The second movableelement 236A surrounds the stent 204 and the first movable element 222Ais looped through the second movable element 236A.

An additional first movable element 222B along with an additional secondmovable element 236B are incorporated into the medical apparatus 200B.

As shown in FIG. 2D, when tension is applied to the two ends 224 and 226of the first movable element 222A, the first movable element 222A pullson the second movable element 236A, radially compressing at least aportion of the stent 204 as indicated by arrows 228. Similarly, whentension is applied to the two ends 232 and 234 of the additional firstmovable element 222B, the additional first movable element 222B pulls onthe additional second movable element 236B, radially compressing atleast a portion of the stent 204 as indicated by arrows 228.

FIG. 3A is a medical apparatus according to an aspect of the invention.FIG. 3B is an enlarged simplified view of a portion of the medicalapparatus shown in FIG. 3A.

Referring to FIGS. 3A and 3B, the medical apparatus is generallydepicted by reference numeral 300A. The medical apparatus 300A includesa catheter assembly 302, and stent 304 arranged on the proximal endportion of the catheter assembly 302. The stent 304 has an innersurface, an outer surface, and is configured from multiple turns of anundulating element 305. The undulating element 305 may be configured ina ring or helical pattern.

The stent 304 has a proximal end portion 306 and distal end portion 308.The distal end portion 308 is formed into a branch having a first leg310 and a second leg 312.

A graft 314 is arranged about the stent 104.

In one preferred embodiment, the stent 304 and graft 314 are constrainedinto a compacted delivery state by a first sheath 316 and second sheath318. As shown in FIG. 3A, the first sheath 316 has been releasedallowing at least a portion of the stent 304 to expand as shown. Thesecond sheath 318 is coupling the second leg 312 to the catheterassembly 302 as shown.

A tube 320 extends from a proximal end portion to a distal end portionof the catheter assembly 302. The tube 320 is positioned within andsurrounded by the stent 304. The tube 320 is attached to the catheterassembly 302 and not attached to the stent 304 or graft 314. A movableelement 322 having a first end 324 and second end 326 surrounds thestent 304 and graft 314. The first end 324 and second end 326 of themovable element 322 extend out a distal end portion of the tube 320. Themovable element 322 is threaded through the tube from a distal end to aproximal end and is looped around the proximal end portion 306 of thestent 304 and graft 314. A further embodiment for “surrounding” thestent with the moveable element includes threading the moveable element322 through the graft 314 or through the stent 304 as shown in FIG. 3B.As shown in FIG. 3B, the movable element 322 is capable of radiallycompressing at least a portion of the stent 304 as indicated by arrows328 when tension is applied to the movable element ends 324 and 326.Additional movable elements may be added similar to those configurationsdescribed in FIGS. 1D and 2D.

FIG. 3C is an enlarged simplified view of a portion of a medicalapparatus according to an embodiment of the invention. As shown in FIG.3C, second movable element 336 is in communication with first movableelement 322. The second movable element 336 surrounds the stent member304 and the first movable element 322 is looped through the secondmovable element 336. The second movable element 336 may also be threadedthrough the graft 314 or threaded through the stent 304 as shown in FIG.3C.

The first end 324 and second end 326 of the first movable element 322extend out a distal end portion of the tube 320. For example, the firstmovable element 322 is threaded through the tube from a distal end to aproximal end and is looped through the second movable element 336.

As shown in FIG. 3C, when tension is applied to the two ends 324 and 326of the first movable element 322, the first movable element 322 pulls onthe second movable element 336, radially compressing at least a portionof the stent 304 as indicated by arrows 328. Additional movable elementsmay be added similar to those configurations described in FIGS. 1D and2D.

FIG. 4A is a medical apparatus according to an embodiment of theinvention. FIG. 4B is an enlarged simplified view of a portion of thethe medical apparatus shown in FIG. 4A.

Referring to FIGS. 4A and 4B, the medical apparatus is generallydepicted by reference numeral 400. The medical apparatus 400 includes acatheter assembly 402, and stent 404 arranged on the proximal endportion of the catheter assembly 402. The stent 404 has an innersurface, an outer surface, and is configured from multiple turns of anundulating element 405. The undulating element 405 may be configured ina ring or helical pattern.

The stent 404 has a proximal end portion 406 and distal end portion 408.The distal end portion 408 is formed into a branch having a first leg410 and a second leg 412.

A graft 414 is arranged about the stent 404.

The stent 404 and graft 414 are constrained into a compacted deliverystate by a first sheath 416 and second sheath 418. As shown in FIG. 4A,the first sheath 416 has been released allowing at least a portion ofthe stent 404 to expand as shown. The second sheath 418 is coupling thesecond leg 412 to the catheter assembly 402 as shown.

A tube 420 extends from a proximal end portion to a distal end portionof the catheter assembly 402. The tube 420 is positioned adjacent theouter surface of the stent 404 and graft 414. The tube 420 is attachedto the catheter assembly 402 and not attached to the stent 404 or graft414. A second movable element 436 is in communication with a firstmovable element 422. The second movable element 436 surrounds the stent404. The second movable element 436 is looped through the first movableelement 422. A release pin 450 is threaded through the second movableelement 436, thereby releasably attaching the second movable element 436to the first movable element 422.

The first end 424 and second end 426 of the first movable element 422extend out a distal end portion of the tube 420 along with the distalend of the release pin 450.

As shown in FIG. 4B, when tension is applied to the two ends 424 and 426of the first movable element 422, the first movable element 422 pulls onthe second movable element 436, radially compressing at least a portionof the stent as previously shown, for example, in FIG. 2B.

The release pin 450 can be translated in a distal direction as shown bydirection arrow 452, thereby releasing the second movable element 436from the first movable element 422.

FIG. 5A is a medical apparatus according to an embodiment of theinvention. FIG. 5B is an enlarged simplified view of a portion of themedical apparatus shown in FIG. 5A.

Referring to FIGS. 5A and 5B, the medical apparatus is generallydepicted as reference numeral 500. The medical apparatus 500 includes acatheter assembly 502, and stent 504 arranged on the proximal endportion of the catheter assembly 502. The stent 504 has an innersurface, an outer surface, and is configured from multiple turns of anundulating element 505. The undulating element 505 may be configured ina ring or helical pattern.

The stent 504 has a proximal end portion 506 and distal end portion 508.The distal end portion 508 is formed into a branch having a first leg510 and a second leg 512.

A graft 514 is arranged about the stent 504.

In a preferred embodiment, the stent 504 and graft 514 are constrainedinto a compacted delivery state by a first sheath 516 and second sheath518. As shown in FIG. 5A, the first sheath 516 has been releasedallowing at least a portion of the stent 504 to expand as shown. Thesecond sheath 518 is coupling the second leg 512 to the catheterassembly 502 as shown.

A tube 520 extends from a proximal end portion to a distal end portionof the catheter assembly 502. The tube 520 is positioned adjacent theouter surface of the stent 504 and graft 514. The tube 520 is attachedto the catheter assembly 502 and not attached to the stent 504 or graft514.

A movable element 522 is threaded through the tube 520 and iscircumferentially arranged around the stent 504. The movable element 522is looped over release pin 550, thereby releasably attaching the movableelement 522 to the release pin 550.

As shown in FIG. 5B, when tension is applied to the two ends 524 and 526of the movable element, the movable element 522 radially compresses atleast a portion of the stent as previously shown, for example, in FIG.2B. When desired, the release pin 550 can be translated in a distaldirection as shown by direction arrow 552, thereby releasing the movableelement 522 from the release pin 550 allowing the movable element 522 tobe withdrawn.

FIG. 6A is a medical apparatus according to an embodiment of theinvention. FIG. 6B is an enlarged simplified view of a portion of themedical apparatus shown in FIG. 6A.

Referring to FIGS. 6A and 6B, the medical apparatus is generallydepicted as reference numeral 600. The medical apparatus 600 includes acatheter assembly 602, and stent 604 arranged on the proximal endportion of the catheter assembly 602. The stent 604 has an innersurface, an outer surface, and is configured from multiple turns of anundulating element 605. The undulating element 605 may be configured ina ring or helical pattern.

The stent 604 has a proximal end portion 606 and distal end portion 608.The distal end portion 608 is formed into a branch having a first leg610 and a second leg 612.

A graft 614 is arranged about the stent 604. The stent 604 and graft 614are constrained into a compacted delivery state (or first diameter) by afirst sheath 616 and second sheath 618. As shown in FIG. 6A, the firstsheath 616 has been released allowing at least a portion of the stent604 to expand as shown. The second sheath 618 is coupling the second leg612 to the catheter assembly 602 as shown.

After the release of the first sheath 616, the stent 604 is allowed toself expand into a second diameter that is greater than the initialcompacted first diameter. The second diameter is defined by a secondaryconstraint 654. The secondary constraint 654 can be comprised, forexample, of a flexible filament that encircles a proximal end portion606 of the stent and graft. The secondary constraint 654 preventsfurther self expansion of the stent.

As shown in FIG. 6B, the secondary constraint 654 is looped around thestent (not shown) and is threaded through a first end of the secondaryconstraint 654. The second end of the secondary constraint 654 is loopedonto a release pin 650. Once the apparatus 600 is properly positionedwithin a vessel target site, the secondary constraint 654 can bereleased by translating the release pin 650 in a distal direction asshown by direction arrow 652. By translating the release pin 650, thestent is released from the secondary constraint and thereby allowed tofurther expand into a third diameter that is greater than the second andfirst diameters.

Optionally, a retrieval cord or filament 656 can be used to join thesecondary constraint 654 to the release pin 650. Therefore when therelease pin is translated distally, the secondary constraint 654 iswithdrawn along with the release pin 650.

FIG. 7A is a medical apparatus according to an embodiment of theinvention. FIG. 7B is an enlarged simplified view of a portion of themedical apparatus shown in FIG. 7A.

Referring to FIGS. 7A and 7B, the medical apparatus is generallydepicted as reference numeral 700. The medical apparatus 700 includes acatheter assembly 702, and stent 704 arranged on the proximal endportion of the catheter assembly 702. The stent 704 has an innersurface, an outer surface, and is configured from multiple turns of anundulating element 705. The undulating element 705 may be configured ina ring or helical pattern.

The stent 704 has a proximal end portion 706 and distal end portion 708.The distal end portion 708 is formed into a branch having a first leg710 and a second leg 712.

A graft 714 is arranged about the stent 704. The stent 704 and graft 714are constrained into a compacted delivery state (or first diameter) by afirst sheath 716 and second sheath 718. As shown in FIG. 7A, the firstsheath 716 has been released allowing at least a portion of the stent704 to expand as shown. The second sheath 718 is coupling the second leg712 to the catheter assembly 702 as shown.

After the release of the first sheath 716, the stent 704 is allowed toself expand into a second diameter that is greater than the initialcompacted first diameter. The second diameter is defined by a secondaryconstraint 754. The secondary constraint 754 is comprised of a flexibleband that encircles a proximal end portion 706 of the stent graft. Thesecondary constraint prevents further self expansion of the stent graft.

As shown in FIG. 7B, the secondary constraint 754 is looped around thestent and is threaded through a latch 758 located near a first end ofthe secondary constraint 754. A release pin 750 is threaded through thelatch 758 to prevent further expansion of the secondary constraint 754.Once the apparatus 700 is properly positioned within a vessel targetsite, the secondary constraint 754 can be released by translating therelease pin 750 in a distal direction as shown by direction arrow 752.By translating the release pin 750, the stent 704 is released from thesecondary constraint 754 and thereby allowed to further expand into athird diameter that is greater than the second and first diameters.Optionally, a retrieval cord or filament 756 can be used to join thesecondary constraint 754 to the release pin 750. Therefore when therelease pin is translated distally, the secondary constraint 754 iswithdrawn along with the release pin 650.

FIGS. 8A through 8C depict a medical apparatus according to anembodiment of the invention.

Referring to FIGS. 8A through 8C, the medical apparatus is generallydepicted as reference numeral 800. The medical apparatus 800 includes acatheter assembly 802, and stent arranged on the proximal end portion ofthe catheter assembly 802. As shown in FIG. 8A the medical apparatus 800has a stent constrained into a small delivery diameter 856. The stent isheld in this small delivery diameter by constraining sheaths 850 and854. The sheath 850 constrains the trunk of the stent while the sheath854 constrains the extended leg portion of the stent. A thirdconstraining sheath 852 is contained within the sheath 850.

Referring to FIG. 8B, when the medical apparatus 800 is positionedwithin a target site, the sheath 850 can be released, allowing at leasta portion of the stent to expand to a diameter 858 that is larger thanthe initial small delivery diameter 856. The sheath 852 thereforeconstrains the stent 804 to an intermediate diameter. The sheath 854constrains the extended leg portion of the stent onto the catheterassembly 802, thereby allowing the medical apparatus to be repositioned,rotated or precisely aligned to the target site. As shown in FIG. 8C,when the medical apparatus is precisely positioned, the sheath 852 canbe released, allowing the stent to fully expand to a large deployeddiameter 860. The deployed diameter 860 is larger than the intermediatediameter 858. The intermediate diameter 858 is larger than the deliverydiameter 856 as shown in FIGS. 8A through 8C. Stent anchoring barbs orhooks 862 (when provided) are therefore constrained to the intermediatediameter 858 during final manipulation and positioning of the medicalapparatus and allowed to expand and engage a vessel when theconstraining sheath 852 is released.

FIG. 9A is a partial side view of a medical apparatus 900, having aconstrained medical device 960 located near or at the distal end of acatheter assembly 962. The catheter assembly 962 has a catheter shaft964 and a distal guidewire port 966. FIG. 9B is a cross-sectional viewof the catheter shaft 964. Shown contained within the catheter shaft 964is a guidewire 970, a release member 972 and an adjustment member 974.The release member can be a cord, thread, wire, pin, tube or otherelement used to release a stent (or other medical device) from aconstraint, thereby allowing the device to expand from a first compacteddelivery profile to a second larger profile. The adjustment member canbe a cord, thread, wire, pin, tube or other element used to alter thesecond profile of at least a portion of the medical device. A catheterused to deliver a medical apparatus can have one, two, three, four orfive or more release members combined with one, two, three, four or fiveor more adjustment members. The release members and adjustment memberscan be contained in separate or shared lumens within the catheter shaft964.

FIGS. 10A and 10B show generalized views of a medical apparatusaccording to an embodiment of the invention (previously described inFIGS. 2A and 2B). Shown in FIG. 10A is a medical apparatus 1000,comprised of a stent 1002 having anchor barbs or hooks 1004. Shown is atube 1006 having a first movable element 1008 located therein. The firstmovable element 1008 is shown looped through a second movable element1010. As shown in FIG. 10B, when tension 1012 is applied to the ends ofthe first movable element 1008, the second movable element 1010 is drawninto the tube 1006. When the second movable element 1010 is drawn intothe tube 1006, the stent graft is compressed in the direction indicatedby arrows 1014. The anchors or barbs 1004 are therefore retracted andpulled inwardly away from a vessel wall. The retraction of the anchorsor barbs will allow the medical apparatus 1000 to be longitudinallyand/or rotationally adjusted. When in the precise target area thetension 1012 on the movable element can be removed, allowing the stentto self expand and engage the anchors or barbs into a vessel wall.

FIGS. 10C through 10H show a generalized delivery sequence according toan embodiment of the invention. Shown in FIG. 10C is a medical apparatus1000, having a first constraining sheath 1020, a second constrainingsheath 1022 and a catheter assembly 1024. Constrained and containedwithin the first and second sheaths 1020, 1022 is a bifurcated stenthaving a trunk, a first short leg and a second long leg. As shown inFIG. 10D, when the medical apparatus is positioned at a target site, thefirst constraining sheath 1020 is released allowing a portion of thestent and first short leg to self expand. A portion of the stent is heldin a constrained small diameter state by movable element 1026. Themovable element 1026 is located in tube 1028. The stent anchors or barbs1030 are constrained and pulled inwardly by the movable element 1026, sothat the anchors or barbs do not engage a vessel wall. The secondconstraining sheath 1022 compresses the stent graft second long leg ontothe catheter assembly 1024. Thus the medical apparatus is captured bythe catheter assembly, allowing subsequent repositioning of the medicalapparatus.

As shown in FIG. 10E, the medical apparatus 1000 can now be readjustedin the longitudinal direction 1032 and/or in the angular direction 1034through manipulations of the catheter assembly 1024.

As shown in FIG. 10F, when the medical apparatus is preciselypositioned, tension on first movable element 1036 is relaxed, allowingsecond movable element 1038 to expand. As second movable element 1038expands, the stent is allowed to further expand in the direction 1040,engaging the anchors or barbs 1030 into a vessel wall.

As shown in FIG. 10G, the second constraining sheath 1022 can bereleased, allowing the second long leg to self expand.

As shown in FIG. 10H, one end of first movable element 1036 can betensioned, allowing first movable element 1036 to be un-looped fromsecond movable element 1038. First movable element 1036 can then bewithdrawn through the tube 1028. The expanded stent graft is nowunattached from the catheter assembly, allowing withdrawal 1042 of thecatheter assembly.

It will be apparent to those skilled in the art that variousmodifications and variation can be made in the present invention withoutdeparting from the spirit or scope of the invention. Thus, it isintended that the present invention cover the modifications andvariations of this invention provided they come within the scope of theappended claims and their equivalents.

What is claimed is:
 1. A stent graft delivery system, said deliverysystem comprising: a catheter; a stent graft arranged on a proximal endportion of the catheter; a fiber having first and second ends, the fiberbeing folded to form a bend, the fiber having first and second portionsextending respectively between the first and second ends of the fiberand the bend in the fiber, the first and second portions of the fiberextending circumferentially around the stent graft and through thecatheter; and a release pin extending through the catheter, the releasepin releasably coupled to the fiber, wherein the stent graft iscompressed by the first and second portion of the fiber in response totensioning of at least one of the first and second ends of the fiber,and wherein disengagement of the release pin from the fiber allowsremoval of the fiber from the system through the catheter.
 2. The stentgraft delivery system as set forth in claim 1, wherein the stent graftincludes a trunk portion.
 3. The stent graft delivery system as setforth in claim 2 including a first sheath releasably constraining thestent graft toward a compacted delivery state suitable for endoluminaldelivery.
 4. The stent graft delivery system as set forth in claim 3,wherein the first sheath extends about the trunk portion of the stentgraft.
 5. The stent graft delivery system as set forth in claim 4,wherein the stent graft includes a leg portion having first and secondlegs each extending from an end of the trunk portion.
 6. The stent graftdelivery system as set forth in claim 5 including a second sheathreleasably constraining the stent graft toward the compacted deliverystate.
 7. The stent graft delivery system as set forth in claim 6,wherein the second sheath extends about the leg portion of the stentgraft.
 8. The stent graft delivery system as set forth in claim 1,wherein the stent graft is compressed by the first and second portion ofthe fiber in response to tensioning of both the first and second ends ofthe fiber.
 9. The stent graft delivery system as set forth in claim 1,wherein the release pin extends through the bend in the fiber.
 10. Thestent graft delivery system as set forth in claim 9, whereindisplacement of the release pin from the bend in the fiber allowsremoval of the fiber through the system through the catheter.
 11. Thestent graft delivery system as set forth in claim 1, wherein the firstand second portions of the fiber extend circumferentially around aproximal portion of the stent graft.
 12. The stent graft delivery systemas set forth in claim 1, wherein the stent graft includes an innersurface defining a lumen and an opposite outer surface.
 13. The stentgraft delivery system as set forth in claim 12, wherein the catheterextends along the outer surface of the stent graft.
 14. The stent graftdelivery system as set forth in claim 13, wherein the catheter issubstantially parallel with a longitudinal axis of the stent graftduring endoluminal delivery and deployment of the stent graft.
 15. Thestent graft delivery system as set forth in claim 12, wherein thecatheter extends through the stent graft lumen.
 16. The stent graftdelivery system as set forth in claim 15, wherein the fiber extends fromthe catheter inside the stent graft lumen and through a graft portion ofthe stent graft.
 17. The stent graft delivery system as set forth inclaim 15, wherein the fiber extends from the catheter inside the stentgraft lumen and through a stent portion of the stent graft.
 18. Amedical apparatus, comprising: a catheter having a proximal end portionand a distal end portion; a stent member having a trunk and a legportion and arranged on the proximal end portion of the catheter,wherein the stent member has an inner surface and an outer surface; afirst sheath material covering the trunk portion of the stent member,wherein the first sheath material is configured to maintain the stentmember at a first diameter suitable for endoluminal delivery; a secondsheath material covering the stent member, wherein the second sheathmaterial is configured to maintain the stent member at a seconddiameter, wherein the second diameter is greater than the first diameterand less than a fully expanded deployed diameter; and a third sheathmaterial covering at least a portion of the leg portion, wherein thethird sheath material is configured to maintain the leg portion of thestent member at the first diameter.
 19. The medical apparatus of claim18, wherein the first sheath material extends over both the stent memberand the second sheath material.
 20. The medical apparatus of claim 19,wherein the second sheath material is disposed between the stent memberand the first sheath material, wherein the stent member is configured toexpand to the second diameter upon a release of the first sheathmaterial, the second sheath material configured to maintain the stentmember at the second diameter.
 21. The medical apparatus of claim 20,wherein the stent member is configured such that the trunk expands uponthe release of the first sheath material.
 22. The medical apparatus ofclaim 20, wherein the stent member includes anchors along the distal endthereof for engaging a vessel.
 23. The medical apparatus of claim 22,wherein the second sheath material is configured to constrain theanchors after the release of the first sheath material and prior to thestent member expanding to the fully expanded deployed diameter.
 24. Themedical apparatus of claim 18, wherein one or more of the first andsecond sheaths is formed from ePTFE film.
 25. An apparatus, comprising:a catheter having a proximal end portion and a distal end portion; astent member arranged on the proximal end portion of the catheter,wherein the stent member has an inner surface and an outer surface; afirst sheath material covering at least a first portion of the stentmember, wherein the first sheath material is configured to maintain thefirst portion of the stent member at a first diameter; and a secondsheath material covering at least a second portion of the stent member,wherein the second sheath material is configured to maintain the secondportion of the stent member at a second diameter, wherein the seconddiameter is greater than the first diameter.
 26. The apparatus of claim25, wherein a length of the first sheath material is substantiallylonger than a length of the second sheath material.
 27. The apparatus ofclaim 25, wherein the stent member is self-expandable.
 28. The apparatusof claim 25, wherein one or more of the first and second sheathmaterials are configured for removal from an implantation site.
 29. Theapparatus of claim 25, wherein a length of the first sheath material issubstantially equal to a length of the second sheath material.
 30. Theapparatus of claim 25, wherein the first and second portions are thesame portion.
 31. The apparatus of claim 25, wherein the first diameteris a compacted delivery diameter, the apparatus further comprising athird sheath material that is configured to maintain a third portion ofthe stent member at the compacted delivery diameter while the secondsheath material is configured to simultaneously maintain the stentmember at the second diameter.
 32. The apparatus of claim 31, whereinone or more of the first and second and third sheath materials areremovable from an implantation site.